SLR visa requirement

I filled out my SLR for Davis, but it requires me to upload my mother’s green card. Why? and do I take a picture of both sides of the green card to upload?

We are in the same boat, they wanted a copy of both my and my husband’s green card - I think it is for residency purposes to determine tuition rates if the student is under 24 (or 22? I can’t remember). Anyway we have been resident in CA for 10 years. We just took a copy of the front of the card and uploaded that, if they need to see the back, I’m sure they’ll ask…